Low-emissivity glass is glass on which a low-emissivity layer including a metal such as silver (Ag) having high reflectance in an infrared range is deposited as a thin film. The low-emissivity glass is a functional material providing energy saving effects by reflecting solar radiation in summer while trapping infrared rays generated from an indoor heater in winter.
Generally, low-e glass deposited by sputtering is soft low-e glass, and has a drawback in that the soft low-e glass cannot be used while a coating surface thereof is exposed to the outside in manufacture of multilayer insulating glass due to a problem of lower durability (for example, abrasion resistance and acid resistance) than hard low-e glass. In addition, since the coating surface of the soft low-e glass is likely to suffer from damage in the process of manufacturing the multilayer insulating glass, special attention is required in the manufacture process. Further, the soft low-e glass still has problems to be overcome, such as constraints in storage period until manufacture of the multilayer insulating glass after production of coating glass, and the like.